Display device

ABSTRACT

According to one embodiment, a display device includes a first substrate, a second substrate opposed to the first substrate and including an end portion, a liquid crystal layer provided between the first substrate and the second substrate and including a polymer in a shape of a streak and a liquid crystal molecule, a light-emitting element having a light emitting portion opposed to the end portion, and a light guide located between the end portion and the light emitting portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.16/357,518 filed Mar. 19, 2019, and is based upon and claims the benefitof priority from Japanese Patent Application No. 2018-059854, filed Mar.27, 2018, the entire contents of each of which are incorporated hereinby reference.

FIELD

Embodiments described herein relate generally to a display device.

BACKGROUND

Recently, various display devices have been proposed. In one example, adisplay device which comprises a color filter between a polymerdispersed liquid crystal layer and a reflective layer and realizes colordisplay by using light reflected off the reflective layer is disclosed.In another example, a mirror-type display device which comprises areflective layer on an upper substrate, provides a mirror function bythe reflective layer and also provides a display function of displayingan image in an opening area of the reflective layer is disclosed.

On the other hand, various illumination devices using polymer dispersedliquid crystal capable of switching between a scattering state ofscattering incident light and a transmitting state of transmittingincident light are proposed.

Incidentally, degradation of display quality needs to be suppressed inthe display device using polymer dispersed liquid crystal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing a configuration example of a displaydevice DSP according to the present embodiment.

FIG. 2 is a perspective view showing the display device DSP shown inFIG. 1.

FIG. 3 is a cross-sectional view showing the display device DSP shown inFIG. 1.

FIG. 4 is a schematic view showing the way the light propagates in thedisplay device DSP of the present embodiment.

FIG. 5 is a cross-sectional view showing a configuration example of thedisplay panel PNL shown in FIG. 3.

FIG. 6 is a schematic view showing a liquid crystal layer 30 in an offstate.

FIG. 7 is a schematic view showing the liquid crystal layer 30 in an onstate.

FIG. 8 is a cross-sectional view showing the display panel PNL in a casewhere the liquid crystal layer 30 is in the off state.

FIG. 9 is a cross-sectional view showing the display panel PNL in a casewhere the liquid crystal layer 30 is in the on state.

FIG. 10 is a cross-sectional view showing another configuration exampleof the display device DSP.

FIG. 11 is a cross-sectional view showing another configuration exampleof the display device DSP.

DETAILED DESCRIPTION

In general, according to one embodiment, a display device comprises afirst substrate, a second substrate opposed to the first substrate andincluding an end portion, a liquid crystal layer provided between thefirst substrate and the second substrate and including a polymer in ashape of a streak and a liquid crystal molecule, a light-emittingelement having a light emitting portion opposed to the end portion, anda light guide located between the end portion and the light emittingportion.

Embodiments will be described hereinafter with reference to theaccompanying drawings. The disclosure is merely an example, and properchanges in keeping with the spirit of the invention, which are easilyconceivable by a person of ordinary skill in the art, come within thescope of the invention as a matter of course. In addition, in somecases, in order to make the description clearer, the widths,thicknesses, shapes, etc., of the respective parts are illustrated inthe drawings schematically, rather than as an accurate representation ofwhat is implemented. However, such schematic illustration is merelyexemplary, and in no way restricts the interpretation of the invention.In addition, in the specification and drawings, structural elementswhich function in the same or a similar manner to those described inconnection with preceding drawings are denoted by like referencenumbers, detailed description thereof being omitted unless necessary.

FIG. 1 is a plan view showing a configuration example of a displaydevice DSP according to the present embodiment. A first direction X, asecond direction Y and a third direction Z are orthogonal to each otherin the drawing but may intersect at an angle other than 90 degrees. Inthe present specification, a position on the leading end side of anarrow indicating the third direction Z may be referred to as “above” anda position on the side opposite to the leading end of the arrow may bereferred to as “below” in some cases. In the case of “a second memberabove a first member” and the case of “a second member below a firstmember”, the second member may be in contact with the first member ormay be away from the first member. In addition, an observation positionat which the display device DSP is observed is assumed to be located onthe leading end side of the arrow indicating the third direction Z, anda view from the observation position toward an X-Y plane defined by thefirst direction X and the second direction Y is referred to as planarview.

In the present embodiment, a display device employing polymer dispersedliquid crystal will be described as an example of the display deviceDSP. The display device DSP comprises a display panel PNL and wiringsubstrates F1 to F3. The display device DSP further comprises a lightsource unit (not shown).

The display panel PNL comprises a first substrate SUB1 and a secondsubstrate SUB2. The first substrate SUB1 and the second substrate SUB2are formed in the shape of a flat plate parallel to the X-Y plane. Thefirst substrate SUB1 and the second substrate SUB2 overlap each other inplanar view. The display panel PNL comprises a display area DA on whichan image is displayed and a frame-shaped non-display area NDA whichsurrounds the display area DA. The display area DA is located in an areain which the first substrate SUB1 and the second substrate SUB2 overlapeach other. The display panel PNL comprises n scanning lines G (G1 toGn) and m signal lines S (S1 to Sm) in the display area DA. Each of nand m is a positive integer, and n may be equal to or different from m.The scanning lines G extend in the first direction X and are spacedapart and arranged in the second direction Y. The signal lines S extendin the second direction Y and are spaced apart and arranged in the firstdirection X.

The first substrate SUB1 comprises end portions E1 and E12 extending inthe first direction X and end portions E13 and E14 extending in thesecond direction Y. The second substrate SUB2 comprises end portions E21and E22 extending in the first direction X and end portions E23 and E24extending in the second direction Y. In the example illustrated, the endportions E11 and E21, the end portions E13 and E23, and the end portionsE14 and E24 overlap, respectively, in planar view. However, these endportions do not necessarily overlap. The end portion E22 is locatedbetween the end portion E12 and the display area DA in planar view. Thefirst substrate SUB1 comprises an extension portion Ex between the endportion E12 and the end portion E22.

The wiring substrates F1 to F3 are connected to the extension portion Exand are arranged in this order in the first direction X. The wiringsubstrate F1 comprises a gate driver GD1. The wiring substrate F2comprises a source driver SD. The wiring substrate F3 comprises a gatedriver GD2. The wiring substrates F1 to F3 may be replaced with a singlewiring substrate.

The signal lines S are drawn to the non-display area NDA and areconnected to the source driver SD. The scanning lines G are drawn to thenon-display area NDA and are connected to the gate drivers GD1 and GD2.In the example illustrated, odd-numbered scanning lines G are drawnbetween the end portion E14 and the display area DA and are connected tothe gate driver GD2. In addition, even-numbered scanning lines G aredrawn between the end portion E13 and the display area DA and areconnected to the gate driver GD1. The relationship in connection betweenthe gate drivers GD1 and GD2 and the scanning lines G is not limited tothe example illustrated.

FIG. 2 is a perspective view showing the display device DSP shown inFIG. 1. Illustration of the wiring substrates F1 to F3 is omitted. Alight source unit LU is located on the first substrate SUB1 and isdisposed along the end portion E22. The light source unit LU compriseslight-emitting elements LS corresponding to light sources and a wiringsubstrate F4 shown by a two-dot chain line. The light-emitting elementsLS are spaced apart and arranged in the first direction X. Each of thelight-emitting elements LS is connected to the wiring substrate F4. Thelight-emitting elements LS are located between the first substrate SUB1and the wiring substrate F4. The wiring substrate F4 may be locatedbetween the first substrate SUB1 and the light-emitting elements LS. Thelight-emitting elements LS are, for example, light-emitting diodes(LEDs). Each of the light-emitting elements LS comprises a lightemitting portion EM opposed to the end portion E22. Although notdescribed in detail, the light emitting portion EM comprises a red lightemitting portion, a green light emitting portion and a blue lightemitting portion. The light emitting portion EM may comprise a cyanlight emitting portion, a magenta light emitting portion and a yellowlight emitting portion. These light emitting portions are provided inthe light emitting portion EM shown by a dotted line in FIG. 2. However,these light emitting portions are not necessarily located in line in thefirst direction X. That is, these light emitting portions may beprovided at different heights in the third direction Z from the firstsubstrate SUB1.

A light guide LG is located between the second substrate SUB2 and thelight-emitting elements LS. In the example illustrated, the secondsubstrate SUB2, the light guide LG and the light-emitting elements LSare arranged in this order in the second direction Y. In addition, thesecond substrate SUB2, the light guide LG and the light-emittingelements LS are located on an upper surface SUB1A side of the firstsubstrate SUB1.

The light guide LG has the function of guiding the light emitted fromthe light emitting portions EM to the end portion E22. The light guideLG has the shape of a rectangular prism extending in the first directionX. That is, the light guide LG has a first surface LG1 opposed to thelight emitting portions EM and a second surface LG2 opposed to the endportion E22. The first surface LG1 and the second surface LG2 areparallel to each other. For example, each of the first surface LG1 andthe second surface LG2 is a flat surface parallel to an X-Z planedefined by the first direction X and the third direction Z. As will bedescribed later, a first height of the first surface LG1 is greater thana second height of the second surface LG2.

The light guide LG further has a third surface LG3 and a fourth surfaceLG4 between the first surface LG1 and the second surface LG2. The thirdsurface LG3 is opposed to the first substrate SUB1 and is, for example,a flat surface parallel to the X-Y plane. The fourth surface LG4 islocated on the side opposite to the third surface LG3 and is inclinedwith respect to the third surface LG3. That is, the fourth surface LG4is a flat surface intersecting the first direction X, the seconddirection Y and the third direction Z.

FIG. 3 is a cross-sectional view showing the display device DSP shown inFIG. 1. Only main portions in the cross-section of the display deviceDSP in a Y-Z plane defined by the second direction Y and the thirddirection Z will be described. The display panel PNL comprises a liquidcrystal layer 30 held between the first substrate SUB1 and the secondsubstrate SUB2. The first substrate SUB1 and the second substrate SUB2are bonded together by a sealant 40. The first substrate SUB1 has anupper surface SUB1A opposed to the second substrate SUB2. The secondsubstrate SUB2 has an upper surface SUB2 on the side opposite to theliquid crystal layer 30. The upper surface USB2A is located at a heightSUB2H from the upper surface SUB1A. A height in the presentspecification is assumed to be a length or distance in the thirddirection Z (in the direction of the normal to the first substrateSUB1).

In the example illustrated, the light-emitting element LS and the lightguide LG are located on the extension portion Ex. In addition, thelight-emitting element LS is located between the wiring substrates F1 toF3 and the light guide LG. In the light-emitting element LS, a lightemitting portion EM which is the most distant in the third direction Zfrom the upper surface SUB1A is located at a height EMH from the uppersurface SUB1A. The height EMH may be substantially equal to the heightSUB2H or may be greater than the height SUB2H. That is, the lightemitting portion EM located at the highest position among the lightemitting portions EM included in the light-emitting element LS may belocated near the upper surface USB2A.

The light-emitting element LS emits light from the light emittingportion EM toward the end portion E22 via the light guide LG. The lightmade incident from the end portion E22 propagates through the displaypanel PNL in the direction opposite to an arrow indicating the seconddirection Y as will be described later. The light-emitting element LSmay be opposed to the end portions of both of the first substrate SUB1and the second substrate SUB2 and may be opposed to, for example, theend portions E11 and E21.

The light guide LG is bonded to the first substrate SUB1, for example,via an adhesive layer 50 located between the third surface LG3 and theupper surface SUB1A. In addition, the light guide LG may be bonded tothe wiring substrate F4 via an adhesive layer located between the fourthsurface LG4 and the wiring substrate F4 as will be described later. Thefirst surface LG1 has a first height LG1H. The second surface LG2 has asecond height LG2H. The first height LG1H is greater than the secondheight LG2H. An upper end portion LG1T of the first surface LG1 islocated at a position higher than that of an upper end portion LG2T ofthe second surface LG2. In addition, the upper end portion LG1T islocated at a height greater than the height EMH. From the perspective oflight incidence efficiency, the upper end portion LG1T should preferablybe located within a range where the upper end portion LG1T is located ata height not less than the height EMH. The upper end portion LG2T islocated at a height substantially equal to that of the upper surfaceSUB2A. The upper end portion LG2T should preferably be located at aposition lower than the upper surface SUB2A. In the example illustrated,the third surface LG3 orthogonally intersects the first surface LG1 andthe second surface LG2.

The fourth surface LG4 extends at a substantially constant inclinationin the second direction Y from the first surface LG1 to the secondsurface LG2. A reference surface Rf which passes through the upper endportion LG2T and extends parallel to the third surface LG3 is shown by adotted line in the drawing. An angle θ formed between the fourth surfaceLG4 and the reference surface Rf is an acute angle, for example, anangle less than 60°, more preferably, an angle less than 30°. From theperspective of light incidence efficiency, the angel θ should preferablybe less than or equal to 15°.

The light guide LG is away from the light-emitting element LS in theexample illustrated, but the light guide LG may be in contact with thelight-emitting element LS. In addition, the light guide LG is away fromthe second substrate SUB2 in the example illustrated, but the lightguide LG may be in contact with the second substrate SUB2. Air layersshould preferably be interposed between the light-emitting element LSand the light guide LG and between the light guide LG and the secondsubstrate SUB2, respectively. The light guide LG is formed of, forexample, transparent resin such as polymethyl methacrylate (PMMA) orpolycarbonate, transparent glass or the like.

FIG. 4 is a schematic view showing the way the light propagates in thedisplay device DSP of the present embodiment.

FIG. 4 (A) corresponds to a comparative example in which no light guideis disposed between the light-emitting element LS and the secondsubstrate SUB2. If the height EMH from the upper surface SUB1A to thelight emitting portion EM is substantially equal to the height SUB2Hfrom the upper surface SUB1A to the upper surface SUB2A or the heightEMH is greater than the height SUB2H, part of the light emitted from thelight emitting portion EM is not made incident on the end portion E22and does not contribute to the display on the display panel PNL.Therefore, the light incidence efficiency of the light from the lightsource unit LU to the display panel PNL decreases, and the displayquality may be degraded.

FIG. 4 (B) corresponds to the display device DSP of the presentembodiment, and the light guide LG is provided between the lightemitting portion EM and the end portion E22. The light guide LGcomprises a first surface LG1 having the upper end portion LG1T locatedat a height greater than the height EMH. The fourth surface LG4 is incontact with an air layer. For this reason, the light emitted from thelight emitting portion EM is made incident on the light guide LG,propagates through the light guide LG while being reflected off thethird surface LG3 and the fourth surface LG4, and is made incident onthe display panel PNL from the end portion E22. Accordingly, most of thelight emitted from the light emitting portion EM is guided to the endportion E22 and contributes to the display on the display panel PNL.Therefore, the decrease of light incidence efficiency can be suppressed,and the degradation of display quality can be suppressed.

Furthermore, in the comparative example, if the thickness of the secondsubstrate SUB2 is increased for improving the light incidenceefficiency, this will hinder the reduction of the thickness of thedisplay panel PNL and will increase the weight of the display deviceDSP. On the other hand, according to the present embodiment, thedecrease of the light incidence efficiency can be suppressed without theincrease of the thickness of the second substrate SUB2. In addition,even if the height of the light emitting portion EM varies, the upperend portion LG1T is located at a position sufficiently higher than thelight emitting portion EM located at the highest position, and thedecrease of the light incidence efficiency can be suppressed.

Next, a configuration example of the display panel PNL will bedescribed.

FIG. 5 is a cross-sectional view showing a configuration example of thedisplay panel PNL shown in FIG. 3. The first substrate SUB1 comprises atransparent substrate 10, wiring lines 11, an insulating layer 12, pixelelectrodes 13 and an alignment film 14. The second substrate SUB2comprises a transparent substrate 20, a common electrode 21 and analignment film 22. The transparent substrates 10 and 20 are insulatingsubstrates such as glass substrates or plastic substrates. The wiringlines 11 are formed of a nontransparent metal material such asmolybdenum, tungsten, aluminum, titanium or silver. The illustratedwiring lines 11 extend in the first direction X but may extend in thesecond direction Y. The insulating layer 12 is formed of a transparentinsulating material. The pixel electrodes 13 and the common electrode 21are formed of a transparent conductive material such as indium tin oxide(ITO) or indium zinc oxide (IZO). The pixel electrodes 13 are disposedin the respective pixels PX. The common electrode 21 is disposed acrossthe pixels PX. The alignment films 14 and 22 may be horizontal alignmentfilms having an alignment restriction force substantially parallel tothe X-Y plane or may be vertical alignment films having an alignmentrestriction force substantially parallel to the third direction Z.

The liquid crystal layer 30 is located between the alignment film 14 andthe alignment film 22. The liquid crystal layer 30 comprises polymerdispersed liquid crystal which includes polymers 31 and liquid crystalmolecules 32. For example, the polymers 31 are liquid crystal polymers.The polymers can be obtained by, for example, polymerizing liquidcrystal monomers in the state of being aligned in a predetermineddirection by the alignment restriction force of the alignment films 14and 22. For example, the alignment treatment direction of the alignmentfilms 14 and 22 is the first direction X, and the alignment films 14 and22 have an alignment restriction force in the first direction X. Forthis reason, the polymers 31 are formed in the shape of a streakextending in the first direction X. The liquid crystal molecules 32 aredispersed in the gaps between the polymers 31 and are aligned such thatmajor axes thereof extend in the first direction X.

The polymers 31 and the liquid crystal molecules 32 have opticalanisotropy or refractive anisotropy. The liquid crystal molecules 32 maybe positive liquid crystal molecules having positive dielectricanisotropy or may be negative liquid crystal molecules having negativedielectric anisotropy. The polymers 31 and the liquid crystal molecules32 have different responsivities to an electric field. The responsivityof the polymers 31 to an electric field is lower than the responsivityof the liquid crystal molecules 32 to an electric field. In the enlargedportion in the drawing, the polymers 31 are shown by upward diagonallines and the liquid crystal molecules 32 are shown by downward diagonallines.

FIG. 6 is a schematic view showing the liquid crystal layer 30 in an offstate. The drawing shows a cross-section of the liquid crystal layer 30in the X-Z plane intersecting the second direction Y which is thetraveling direction of the light from the light source unit LU. The offstate corresponds to a state in which no voltage is applied to theliquid crystal layer 30 (for example, a state in which the potentialdifference between the pixel electrode 13 and the common electrode 21 isapproximately zero). An optical axis Ax1 of the polymer 31 and anoptical axis Ax2 of the liquid crystal molecule 32 are parallel to eachother. In the example illustrated, the optical axis Ax1 and the opticalaxis Ax2 are parallel to the first direction X. The polymer 31 and theliquid crystal molecule 32 have substantially equal refractiveanisotropy. That is, the ordinary refractive index of the polymer 31 andthe ordinary refractive index of the liquid crystal molecule 32 aresubstantially equal to each other, and the extraordinary refractiveindex of the polymer 31 and the extraordinary refractive index of theliquid crystal molecule 32 are substantially equal to each other. Forthis reason, hardly any refractive index difference exists between thepolymer 31 and the liquid crystal molecule 32 in all directionsincluding the first direction X, the second direction Y and the thirddirection Z.

FIG. 7 is a schematic view showing the liquid crystal layer 30 in an onstate. The on state corresponds to a state in which voltage is appliedto the liquid crystal layer 30 (for example, a state in which thepotential difference between the pixel electrode 13 and the commonelectrode 21 is greater than or equal to a threshold value). Asdescribed above, the responsivity of the polymer 31 to an electric fieldis lower than the responsivity of the liquid crystal molecule 32 to anelectric field. For example, the alignment direction of the polymer 31hardly changes regardless of whether an electric field exists or not. Onthe other hand, the alignment direction of the liquid crystal molecule32 changes in accordance with an electric field when high voltage whichis greater than the threshold value is applied to the liquid crystallayer 30. That is, as illustrated in the drawing, the optical axis Ax1is substantially parallel to the first direction X, whereas the opticalaxis Ax2 is inclined with respect to the first direction X. If theliquid crystal molecules 32 are positive liquid crystal molecules, theliquid crystal molecules 32 are aligned such that major axes thereofextend along an electric field. The electric field between the pixelelectrode 13 and the common electrode 21 is formed in the thirddirection Z. Therefore, the liquid crystal molecules 32 are aligned suchthat major axes thereof or the optical axes Ax2 extend in the thirddirection Z. That is, the optical axis Ax1 and the optical axis Ax2intersect each other. Therefore, a large refractive index differenceexists between the polymer 31 and the liquid crystal molecule 32 in alldirections including the first direction X, the second direction Y andthe third direction Z.

FIG. 8 is a cross-sectional view showing the display panel PNL in a casewhere the liquid crystal layer 30 is in the off state. A light beam L11emitted from the light-emitting element LS is made incident on the lightguide LG from the first surface LG1, propagates to the second surfaceLG2, is made incident on the display panel PNL from the end portion E22and propagates through the transparent substrate 20, the liquid crystallayer 30, the transparent substrate 10 and the like. If the liquidcrystal layer 30 is in the off state, the light beam L11 is transmittedand hardly scattered in the liquid crystal layer 30. The light beam L11propagates through the display panel PNL and hardly leaks from a lowersurface 10B of the transparent substrate 10 and an upper surface 20T ofthe transparent substrate 20. That is, the liquid crystal layer 30 is ina transparent state.

External natural light L12 which is made incident on the display panelPNL is transmitted and hardly scattered in the liquid crystal layer 30.In other words, the natural light L12 made incident on the display panelPNL from the lower surface 10B is transmitted through the upper surface20T, and the natural light L12 made incident on the display panel PNLfrom the upper surface 20T is transmitted through the lower surface 10B.For this reason, when the user observes the display panel PNL from theupper surface 20T side, the user can visually recognize a background onthe lower surface 10B side through the display panel PNL. Similarly,when the user observes the display panel PNL from the lower surface 10Bside, the user can visually recognize a background on the upper surface20T side through the display panel PNL.

FIG. 9 is a cross-sectional view showing the display panel PNL in a casewhere the liquid crystal layer 30 is in the on state. A light beam L21emitted from the light-emitting element LS is made incident on the lightguide LG from the first surface LG1, propagates to the second surfaceLG2, is made incident on the display panel PNL from the end portion E22and propagates through the transparent substrate 20, the liquid crystallayer 30, the transparent substrate 10 and the like. In the exampleillustrated, the liquid crystal layer 30 overlapping a pixel electrode13A is in the off state and the liquid crystal layer 30 overlapping apixel electrode 13B is in the on state. For this reason, the light beamL21 is transmitted and hardly scattered in an area of the liquid crystallayer 30 which overlaps the pixel electrode 13A, and the light beam L21is scattered in an area of the liquid crystal layer 30 which overlapsthe pixel electrode 13B. Of the light beam L21, some scattered lightbeams L211 are transmitted through the upper surface 20T, some scatteredlight beams L212 are transmitted through the lower surface 10B, and theother scattered light beams propagate through the display panel PNL.

In the area overlapping the pixel electrode 13A, natural light L22 madeincident on the display panel PNL is transmitted and hardly scattered inthe liquid crystal layer 30 similarly to the natural light L12 shown inFIG. 7. In the area overlapping the pixel electrode 13B, when naturallight L23 is made incident from the lower surface 10B, part of thenatural light L23 is scattered in the liquid crystal layer 30 and partof the natural light L23, namely, light L231 is transmitted through theupper surface 20T. In addition, when natural light L24 is made incidentfrom the upper surface 20T, part of the natural light L24 is scatteredin the liquid crystal layer 30 and part of the natural light L24,namely, light L241 is transmitted through the lower surface 10B. Forthis reason, when the user observes the display panel PNL from the uppersurface 20T side, the user can visually recognize the color of the lightbeam L21 in the area overlapping the pixel electrode 13B. In addition,since the light L231 is transmitted through the display panel PNL, theuser can visually recognize the background on the lower surface 10B sidethrough the display panel PNL. Similarly, when the user observes thedisplay panel PNL from the lower surface 10B side, the user can visuallyrecognize the color of the light beam L21 in the area overlapping thepixel electrode 13B. In addition, since the light L241 is transmittedthrough the display panel PNL, the user can visually recognize thebackground on the upper surface 20T side through the display panel PNL.In the area overlapping the pixel electrode 13A, since the liquidcrystal layer 30 is in the transparent state, the user hardly recognizethe color of the light beam L21 and the user can visually recognize thebackground through the display panel PNL.

Next, another configuration example of the present embodiment will bedescribed.

FIG. 10 is a cross-sectional view showing another configuration exampleof the display device DSP. The configuration example of the displaydevice DSP shown in FIG. 10 differs from the configuration example ofthe display device DSP shown in FIG. 3 in that the wiring substrate F4and the light guide LG are bonded together via an adhesive layer 60located between the wiring substrate F4 and the fourth surface LG4. Inthe example illustrated, the light guide LG is also bonded to the firstsubstrate SUB1 with the adhesive layer 50. At least one of the adhesivelayers 50 and 60 may include a reflective layer. Since the wiringsubstrate F4 is bonded to the light guide LG, the light-emitting unit LUcan be fixed to the first substrate SUB1 without interposition of anadhesive layer between the light-emitting element LS connected to thewiring substrate F4 and the first substrate SUB1.

According to this configuration example, advantages similar to those ofthe above-described configuration example can be achieved. In addition,the height EMH of the light emitting portion EM can be reduced ascompared to a case where an adhesive layer is located between thelight-emitting element LS and the first substrate SUB1. For this reason,the thickness of the display panel PNL can be reduced. In addition,since the fourth surface LG4 is covered with the wiring substrate F4,the degradation of visual quality caused by stray light resulting fromleaking light from the fourth surface LG4 can be suppressed.

FIG. 11 is a cross-sectional view showing another configuration exampleof the display device DSP. The configuration example of the displaydevice shown in FIG. 11 differs from the configuration example of thedisplay device DSP shown in FIG. 10 in that a first reflective layer M1is formed on the third surface LG3 and a second reflective layer M2 isformed on the fourth surface LG4.

In one example, the first reflective layer M1 and the second reflectivelayer M2 are formed of a metal material having a high reflectance suchas aluminum, silver, titanium or silver. The first reflective layer M1and the second reflective layer M2 may be formed on the third surfaceLG3 and the fourth surface LG4, respectively, by vapor deposition,coating or printing or may be formed on the third surface LG3 and thefourth surface LG4, respectively, by attaching a separately-formed thinfilm or the like. In addition, the first reflective layer M1 and thesecond reflective layer M2 may have a multilayer structure in which anadhesive, a reflective thin film and an adhesive are stacked in thisorder. The first reflective layer M1 and the second reflective layer M2may be formed entirely on the third surface LG3 and the fourth surfaceLG4, respectively, or may be formed partly on the third surface LG3 andthe fourth surface LG4, respectively.

The second reflective layer M2 and the wiring substrate F4 are incontact with each other in the example illustrated, but if wiring linesare formed on a surface of the wiring substrate F4 which is opposed tothe second reflective layer M2, the wiring substrate F4 shouldpreferably be away from the second reflective layer M2. In addition, ifthe wiring substrate F4 is in contact with the second reflective layerM2, an insulating layer is interposed between the wiring substrate F4and the second reflective layer M2.

According to this configuration example, advantages similar to those ofthe above-described configuration example can be achieved. In addition,the light leaking from the third surface LG3 and the fourth surface LG4can be suppressed, and the light reflection efficiency of the thirdsurface LG3 and the fourth surface LG4 can be improved and the lightusage efficiency can be improved. Only one of the first reflective layerM1 and the second reflective layer M2 may be provided in the light guideLG instead.

As described above, a display device capable of suppressing thedegradation of display quality can be provided by the presentembodiment.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A display comprising: a first substrate; a secondsubstrate opposed to the first substrate; a liquid crystal layerincluding streak-like polymers provided between the first substrate andthe second substrate; a plurality of light-emitting elements arrangedalong a side surface of the second substrate on the first substrate; anda light guide formed of transparent resin on the first substrate andlocated between the light-emitting elements and the side surface of thesecond substrate, wherein the streak-like polymers extend in thedirection that the light-emitting elements are arranged, a first gap isbetween the light-emitting elements and the light guide, and a secondgap is between the light guide and the side surface of the secondsubstrate.
 2. The display device of claim 1, wherein the light guide hasa first thickness on a side at the second substrate and a secondthickness on a side at the light-emitting elements, and the firstthickness is smaller than the second thickness.
 3. The display device ofclaim 2, wherein the light guide is bonded to the first substrate. 4.The display device of claim 3, wherein a lower surface of the lightguide is bonded to the first substrate and is parallel to a main surfaceof the first substrate, and an upper surface of the light guide isinclined at an angle of less than or equal to 15° with respect to themain surface of the first substrate.
 5. The display device of claim 4,further comprising a wiring substrate electrically connected to thelight-emitting elements, wherein the light-emitting elements and thelight guide are provided between the first substrate and the wiringsubstrate.
 6. A display comprising: a first substrate; a secondsubstrate opposed to the first substrate; a liquid crystal layerincluding streak-like polymers provided between the first substrate andthe second substrate; a plurality of light-emitting elements arrangedalong a side surface of the second substrate on the first substrate; alight guide formed of transparent resin on the first substrate andlocated between the light-emitting elements and the side surface of thesecond substrate; a first reflective layer formed on an upper surface ofthe light guide; and a second reflective layer formed on a lower surfaceof the lightguide on the opposite side of the first reflective layer,wherein the streak-like polymers extend in the direction that thelight-emitting elements are arranged, a first gap is between thelight-emitting elements and the light guide, and a second gap is betweenthe light guide and the side surface of the second substrate.
 7. Thedisplay device of claim 6, wherein the second reflective layer is bondedto the first substrate.
 8. The display device of claim 7, wherein thelight guide has a first thickness on a side at the second substrate anda second thickness on a side at the light-emitting elements, and thefirst thickness is smaller than the second thickness.
 9. The displaydevice of claim 6, wherein the first reflective layer is inclined at anangle of less than or equal to 15° with respect to a main surface of thefirst substrate.
 10. The display device of claim 6, further comprising awiring substrate electrically connected to the light-emitting elements,wherein the light-emitting elements and the light guide are providedbetween the first substrate and the wiring substrate.